McDonnell Douglas DC-9-83 N943AS

Summary

On 25 December 2007 at about 17:18 local time, a McDonnell Douglas DC-9-83 registered N943AS, operated by Alaska Airlines, Inc., was involved in an accident near Ontario, California, United States. 114 people were on board and 2 were seriously injured. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

25 December 2007 at 17:18

Classification

Accident

Location

Ontario, California, United States

Nearest airport

Ontario International (ONT)

Coordinates

34.0561, -117.6011

Aircraft

McDonnell Douglas DC-9-83

Registration

N943AS

Category

Airplane

Engines

2

Operator

Alaska Airlines, Inc.

Operating rule

Part 121: Air Carrier

Phase of flight

Not recorded

Route

Seattle → Ontario

Aircraft damage

Not recorded

Weather

VMC

Light

Day

NTSB number

SEA08LA050

2 people were seriously injured.

The lack of turbulence forecasts available to the flight crew, which resulted in the flight attendants not being seated when the flight encountered severe terrain-induced turbulence. Contributing to the accident were the terrain-induced turbulence, the failure of the company that provided the flight's weather briefing to forecast severe turbulence, and the failure of the dispatcher to provide the National Weather Service severe turbulence forecast to the flight.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

Two flight attendants were seriously injured when the airplane encountered severe turbulence while descending for landing. The turbulence was likely the result of strong easterly winds interacting with the rough terrain in the area (mechanical turbulence). The flight data recorder data indicates that the airplane experienced a vertical acceleration of +0.4 G to +1.9 G, or 1.5 G total change, which corresponds to severe turbulence. The National Weather Service forecast the severe turbulence in Significant Meteorological Advisory (SIGMET) Victor 2, which was issued before the flight departed. The weather company that provides weather information to the operator did not forecast severe turbulence for the area. The content of SIGMET Victor 2 was available to the flight's dispatcher. However, this information was not provided to the flight crew. The two flight attendants who sustained injuries were both standing, completing final cabin duties in preparation for landing, and were knocked to the floor during the turbulence encounter.

Quoted verbatim from the NTSB record.